Problem with .css and Firefox

Problem with .css and Firefox

The .css for the checkbox in the following example (from the jQuery documentation) works fine with IE but is ignored in FF. Why?

TIA,

l. woods

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<script src="http://code.jquery.com/jquery-latest.js"></script>

<script>
$(document).ready(function(){

var input = $(":checkbox").css({background:"blue", border:"3px red solid"});
$("div").text("For this type jQuery found " + input.length + ".")
.css("color", "red");
$("form").submit(function () { return false; }); // so it won't submit

});
</script>
<style>
textarea { height:45px; }
</style>
</head>
<body>
<form>
<input type="button" value="Input Button"/>
<input type="checkbox" />
<input type="checkbox" />
<input type="file" />
<input type="hidden" />
<input type="image" />
<input type="password" />
<input type="radio" />
<input type="reset" />
<input type="submit" />
<input type="text" />
<select><option>Option<option/></select>
<textarea></textarea>
<button>Button</button>
</form>
<div>
</div>
</body>
</html>